gep

    pub fn gep(
        self: *WipFunction,
        kind: Instruction.GetElementPtr.Kind,
        ty: Type,
        base: Value,
        indices: []const Value,
        name: []const u8,
    ) Allocator.Error!Value {
        const base_ty = base.typeOfWip(self);
        const base_is_vector = base_ty.isVector(self.builder);

        const VectorInfo = struct {
            kind: Type.Vector.Kind,
            len: u32,

            fn init(vector_ty: Type, builder: *const Builder) @This() {
                return .{ .kind = vector_ty.vectorKind(builder), .len = vector_ty.vectorLen(builder) };
            }
        };
        var vector_info: ?VectorInfo =
            if (base_is_vector) VectorInfo.init(base_ty, self.builder) else null;
        for (indices) |index| {
            const index_ty = index.typeOfWip(self);
            switch (index_ty.tag(self.builder)) {
                .integer => {},
                .vector, .scalable_vector => {
                    const index_info = VectorInfo.init(index_ty, self.builder);
                    if (vector_info) |info|
                        assert(std.meta.eql(info, index_info))
                    else
                        vector_info = index_info;
                },
                else => unreachable,
            }
        }
        if (!base_is_vector) if (vector_info) |info| switch (info.kind) {
            inline else => |vector_kind| _ = try self.builder.vectorType(
                vector_kind,
                info.len,
                base_ty,
            ),
        };

        try self.ensureUnusedExtraCapacity(1, Instruction.GetElementPtr, indices.len);
        const instruction = try self.addInst(name, .{
            .tag = switch (kind) {
                .normal => .getelementptr,
                .inbounds => .@"getelementptr inbounds",
            },
            .data = self.addExtraAssumeCapacity(Instruction.GetElementPtr{
                .type = ty,
                .base = base,
                .indices_len = @intCast(indices.len),
            }),
        });
        self.extra.appendSliceAssumeCapacity(@ptrCast(indices));
        return instruction.toValue();
    }